DIY solar battery storage

[binky]

Reply from the DNO. Incidentally, I had to chase and chase it!
Yep, they want a full G99 application due to the AC coupled inverter adding to the theoretical export possibility.
They want the certification of all the proposed equipment and existing.
Also, a full schematic so that they can model whether the grid can accommodate the addition.
I can draw the schematic using Libre Office. I'm wondering if this will be acceptable or will they require a recognised professional electrical drawing? I suppose I can put it in and see if it gets bounced back.

they aren't too fussy about the drawings, example below done is publisher - you don't need it to be so pretty, it's a requirement to attach a schematic adjacent to the inverter of CU, so this is pretty for the customer.

 

[Berserkerboy]

Ah. Excellent. Thank you so much for that Binky. Mine won't be nearly so pretty.

 

[Berserkerboy]

In the process of filling in the G99 application A1.1 and would appreciate a few pointers..

The application is for a 3kw Solis AC coupled inverter (SOL-3.0K-RAI-48ES-5G-AC-V2) along with a Fox 5.2kwh (LV5200) battery to supplement already installed 3.6kw of solar panels with Enphase microinverters.

I presume I should declare that the Solis inverter will be set to limit export to 3.6kw?
Also, do I need to send certification for the battery? I can access some test results online for the Fox battery but the retailers have not sent anything despite my requests.

I attach my effort at a schematic I intend to send to the DNO and welcome comments, especially on any mistakes I have made.. I do not have access to Publisher. If anyone knows of a free software version I could use to make a better diagram I would be very grateful..

 

[steptoe]

@Berserkerboy
I used to just do SLDs , using libredraw,
Don't know if they are still acceptable now tho

 

[Berserkerboy]

Application sent today. I had confirmation from the retailer of the battery that G99 certification is not required as it's the inverter that matters.
So we'll see if the schematic is acceptable. Also whether I need to make a full G100 application.

 

[Berserkerboy]

Hi all.
Just to update. Phone call from the DNO this morning. Our proposal would necessitate the upgrade of the transformer for which we would be charged £6000. Sooooo...We can't have an AC-coupled inverter and the battery. However, microinverters were a no-brainer for us, as our panels face 3 different directions and maximise our self-usage. We just have to accept that energy storage is not possible for our situation I guess. Horrible seeing that export figure on a sunny day. Definitely, doing our bit for the environment though.
Thanks everyone for their contributions. A really good forum. Very educational..

 

[binky]

Hi all.
Just to update. Phone call from the DNO this morning. Our proposal would necessitate the upgrade of the transformer for which we would be charged £6000. Sooooo...We can't have an AC-coupled inverter and the battery. However, microinverters were a no-brainer for us, as our panels face 3 different directions and maximise our self-usage. We just have to accept that energy storage is not possible for our situation I guess. Horrible seeing that export figure on a sunny day. Definitely, doing our bit for the environment though.
Thanks everyone for their contributions. A really good forum. Very educational..

Did they offer a figure you could have? Or would they consider an export limited system?

 

[Berserkerboy]

Hi Binky.
In short no.
My application indicated that we would limit the inverter to 16A backflow. I don't know why it would send anything back.?
But the planner said he had modeled the system and the transformer would need updating.
We live in a cluster of 4 properties. I can see a small transformer on a pole of one of our neighbours from where our supply comes.

 

[Gian]

Hi all.
Just to update. Phone call from the DNO this morning. Our proposal would necessitate the upgrade of the transformer for which we would be charged £6000. Sooooo...We can't have an AC-coupled inverter and the battery. However, microinverters were a no-brainer for us, as our panels face 3 different directions and maximise our self-usage. We just have to accept that energy storage is not possible for our situation I guess. Horrible seeing that export figure on a sunny day. Definitely, doing our bit for the environment though.
Thanks everyone for their contributions. A really good forum. Very educational..

Appoligies for jumping in. Can you not use an off grid system with batterys. Then having an auto or manual switching arrangement like say a generator would use to switch back to grid. My dno want £15k to upgrade my transformer so I can have 3phase. I have and am just testing a goodwe system and I use lead acid leasure battery's. 4x12 48v they run my home for 3 hours at night with an average load of 700w. Once it's tested and fine I will hook up another 48v bank to increase this and add more solar for charging.

 

[binky]

Hi Binky.
In short no.
My application indicated that we would limit the inverter to 16A backflow. I don't know why it would send anything back.?
But the planner said he had modeled the system and the transformer would need updating.
We live in a cluster of 4 properties. I can see a small transformer on a pole of one of our neighbours from where our supply comes.

Persuade your neighbours to allow you submit solar applications in their names, and it will force the DNO to upgrade the tranny for free. One of my customers did that, his property having 4 mpan numbers.

 

[carptench]

Persuade your neighbours to allow you submit solar applications in their names, and it will force the DNO to upgrade the tranny for free. One of my customers did that, his property having 4 mpan numbers.

Hi All
Been following this thread. Binky can you please expand on why the DNO would be forced to upgrade the transformer if it was on the application land?
Reason I ask is we a have 3 phase coming onto a pole next to our house (On our Land). With a single phase transformer. We enquired about putting a 3 phase transformer in a few years ago and they wanted 10k. Do they have to do a free upgrade for renewables?

Thanks
M

 

[binky]

Hi All
Been following this thread. Binky can you please expand on why the DNO would be forced to upgrade the transformer if it was on the application land?
Reason I ask is we a have 3 phase coming onto a pole next to our house (On our Land). With a single phase transformer. We enquired about putting a 3 phase transformer in a few years ago and they wanted 10k. Do they have to do a free upgrade for renewables?

Thanks
M

Ok, the DNO cannot stop you backfeeding 16amps by law. So it's their responsibility to maintain and improve their network, including transformers, when necessary. If there's enough 16amp applications for solar to cause problems with the transformer, then they have to pay for the upgrade. If, on the other hand you try to back feed more 16 amps, then they can charge you for the upgrade. Changing from single to 3 phase for a single property is a different matter, as that is a demand from yourself for an improved electrical connection.

 

[Berserkerboy]

Good call. One of the four properties here already had panels before I installed mine. I'll have a word. Cheers.

 

[Berserkerboy]

Appoligies for jumping in. Can you not use an off grid system with batterys. Then having an auto or manual switching arrangement like say a generator would use to switch back to grid. My dno want £15k to upgrade my transformer so I can have 3phase. I have and am just testing a goodwe system and I use lead acid leasure battery's. 4x12 48v they run my home for 3 hours at night with an average load of 700w. Once it's tested and fine I will hook up another 48v bank to increase this and add more solar for charging.

Sounds interesting but I'd like something a bit more automatic. Be nice to be able to leave a heater on in the living room knowing that we wouldn't be drawing from the grid if the sun went in for a bit.
Now wondering if a heat store might be worth installing to replace our hot water tank so that we store a bit more energy if the battery is a no go.

 

[carptench]

Ok, the DNO cannot stop you backfeeding 16amps by law. So it's their responsibility to maintain and improve their network, including transformers, when necessary. If there's enough 16amp applications for solar to cause problems with the transformer, then they have to pay for the upgrade. If, on the other hand you try to back feed more 16 amps, then they can charge you for the upgrade. Changing from single to 3 phase for a single property is a different matter, as that is a demand from yourself for an improved electrical connection.

Thanks Binky
Didn't realise they would be obliged to do that. Makes total sense regarding a single to three phase upgrade.

 

[binky]

Thanks Binky
Didn't realise they would be obliged to do that. Makes total sense regarding a single to three phase upgrade.

They try to deny their obligations sometimes, but that's the legal position.

 

[ProDave]

We are in that position here. When building the new house, we were only offered a 12KVA supply as that was all the existing transformer could supply. Annoyingly to them probably we accepted that as it's a low energy house and 12KVA is plenty.

Then when I fitted PV (seconf person on this transformer to do so) I notified it, and their first response was to "disconnect it and we will quote for a network upgrade" that was because they had seen "4000" in the inverter model number and assumed it could export (slightly) more than 16A. when I supplied the certificate from the inverter manufacturer they back down and approved the install. They are clearly looking for any opportunity to pin the cost of upgrading this transformer on someone else. But that won't be me.

 

[Berserkerboy]

An update: My G99 application was rejected. Too much possible generation even though application showed additional AC coupled inverter set to zero export. I thought that was that.
However, after eventually speaking to Western Power (10.05.22) it seems like a G100 application may be more successful. Why didn't they suggest this at the time of rejecting the G99 application? Not very helpful!
Anyway, application form is in, with a diagram of the setup and G100 cert for the inverter.
We'll see!
The rep said that they would not need to be a witness of the setup and any associated cost with that, despite what their website says....I hope they record their conversations!

 

[binky]

An update: My G99 application was rejected. Too much possible generation even though application showed additional AC coupled inverter set to zero export. I thought that was that.
However, after eventually speaking to Western Power (10.05.22) it seems like a G100 application may be more successful. Why didn't they suggest this at the time of rejecting the G99 application? Not very helpful!
Anyway, application form is in, with a diagram of the setup and G100 cert for the inverter.
We'll see!
The rep said that they would not need to be a witness of the setup and any associated cost with that, despite what their website says....I hope they record their conversations!

There's one guy at WPD who is a 'jobs worth' sounds like you encountered him. The rest of the team are very helpful indeed.

 

[Berserkerboy]

There's one guy at WPD who is a 'jobs worth' sounds like you encountered him. The rest of the team are very helpful indeed.

Ha ha.. Maybe. When I first made my G98 application they told me to disconnect it immediately as only MCS installers could do solar...!!
As I understand the G100 application. As I already have generation in place, I only need to send the application form with a description of the ELS and relevant system diagram. I have sent the inverter certificate which hopefully covers their failsafe questions.
Normally it takes a few days for them to respond so I wait in anticipation of a problem..